Correction approximating straight line group information generating method of multi-divided reading CCD, and correction processing device manufacturing method of multi-divided reading CCD

ABSTRACT

To make it possible to cope with an error in a hue or the like in the case of using such a CCD of lower quality or an analog circuit of lower quality as might otherwise raise a problem in the hue, a correction approximating straight line group information creating method/apparatus of a multi-divided reading CCD and a correction processing device manufacturing method/apparatus of a multi-divided reading CCD generate correction approximating straight line group information for one real shot optimum for corrections, at an adjusting stage from a plurality of pieces of primary correction approximating straight line group information generated in advance. At the shooting time, therefore, all pixels can be corrected for their individual kinds by making use of the correction approximating straight line group information for one real shot.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an apparatus forgenerating correction approximate straight-line group information formulti-segment reading CCD, and a method and an apparatus formanufacturing correction processing equipment for multi-segment readingCCD.

2. Description of the Related Art

In recent years, CCDs used for cameras and video cameras have beenprovided with a large number of pixels, so that it is necessary to readthe large number of pixels within a specified time. Therefore, as ahigh-speed reading method for a large number of pixels of CCD, amulti-segment reading method, in which all pixels of a CCD are segmentedinto a plurality of areas, and pixels in the segmented areas areconcurrently read, has been used. In this method, a receiving unit ofCCD is segmented into a plurality of blocks, and a horizontaltransferring unit is also segmented, and transfers charge correspondingto each pixel. However, in this CCD, which is segmented into a pluralityof blocks and outputs charge, signal paths between the blocks aredifferent, so that the difference of output values for pixel occursbetween the blocks when the segmented blocks are reconstructed into onescreen. This difference mainly occurs due to the difference of physicalproperties between circuits. The difference is a value unique to eachCCD. In addition, the difference between the segmented blocks isproportionate to the amount of light received by the light-receivingunit. Therefore, in the method disclosed in the cited document (Jpn.unexamined patent publication No. 2002-320142), by correcting gain in anamplification unit, which amplifies the output values for pixel of eachblock, the difference of output values for pixel occurring betweenblocks is corrected.

However, in the above method disclosed in the cited document (Jpn.unexamined patent publication No. 2002-320142), by means of onecorrection approximate straight-line group information, which is commonto all pixels, the difference of output values for pixel occurringbetween blocks is corrected according to an amount of received light ofeach pixels. Therefore, in the case of using a CCD of high quality or ananalog circuit of high quality, in which problems in hue etc. are hardlyobserved, the above method is efficient enough, but in the case of usinga CCD of lower quality or an analog circuit of lower quality, in whichproblems in hue etc. are observed, the above method is not efficientenough to cope with the problems in hue etc. The reason for this is thateach pixel of CCD has a correction property unique to pixel type.

SUMMARY OF THE INVENTION

The present invention will solve the above deficiencies. The method andan apparatus for generating correction approximate straight-line groupinformation for multi-segment reading CCD, and a method and an apparatusfor manufacturing a correction processing equipment for multi-segmentreading CCD of the present invention generates a plurality of firstcorrection approximate straight-line group information with respect toeach apparatus upon adjustment. The one final correction approximatestraight-line group information is generated from the generatedplurality of first correction approximate straight-line groupinformation. Therefore, for all pixels, it becomes possible to carry outcorrection with respect to each pixel type by means of the one finalcorrection approximate straight-line group information uponphotographing.

The first aspect of the present invention is a generating method forcorrection approximate straight-line group information for multi-segmentreading CCD, which is for correcting an output value for pixel acquiredbased on an output in accordance with a pixel type of CCD, comprising aselecting step for illuminant color for correction, which selects aplurality of illuminant colors in accordance with said pixel type ofCCD, an irradiating step for illuminant color for correction, whichirradiates an illuminant color for correction selected in said selectingstep for illuminant color for correction to said CCD, a generating stepfor first correction approximate straight-line group information, whichgenerates first correction approximate straight-line group informationbased on the illuminant color for correction irradiated in saidirradiating step for illuminant color for correction, and a generatingstep for final correction approximate straight-line group information,which generates one final correction approximate straight-line groupinformation with respect to each said pixel type based on the pluralityof first correction approximate straight-line group informationgenerated in said generating step for first correction approximatestraight-line group information.

The second aspect of the present invention is a manufacturing method forcorrection processing equipment for multi-segment reading CCD, which isfor correcting an output value for pixel acquired based on an output inaccordance with a pixel type of CCD, comprising a preparing step forCCD, which prepares a CCD to be corrected by the correction processingequipment, a selecting step for illuminant color for correction, whichselects a plurality of illuminant colors in accordance with said pixeltype of CCD, an irradiating step for illuminant color for correction,which irradiates a illuminant color for correction selected in saidselecting step for illuminant color for correction to said CCD, agenerating step for first correction approximate straight-line groupinformation, which generates first correction approximate straight-linegroup information based on the illuminant color for correctionirradiated in said irradiating step for illuminant color for correction,a generating step for final correction approximate straight-line groupinformation, which generates one final correction approximatestraight-line group information with respect to each said pixel typebased on the plurality of first correction approximate straight-linegroup information generated in said generating step for first correctionapproximate straight-line group information, and a storing step, whichstores the final correction approximate straight-line group informationcorrelated with said CCD, which has been acquired in said generatingstep for final correction approximate straight-line group information,in a memory unit of the correction processing equipment.

According to the method and the apparatus for generating correctionapproximate straight-line group information for multi-segment readingCCD, and a method and an apparatus for manufacturing a correctionprocessing equipment for multi-segment reading CCD of the presentinvention, it becomes possible to generate a plurality of firstcorrection approximate straight-line group information with respect toeach apparatus upon adjustment. The best one final correctionapproximate straight-line group information is generated from thegenerated plurality of first correction approximate straight-line groupinformation. Therefore, as to all pixels, it becomes possible to carryout correction with respect to each pixel type by means of the one finalcorrection approximate straight-line group information uponphotographing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a diagram showing correction approximate straight-line groupinformation of a first embodiment;

FIG. 2 is a schematic diagram showing correction approximatestraight-line group information of the first embodiment;

FIG. 3 is a diagram exemplifying relation between CCD pixels andcorrected values of the first embodiment;

FIG. 4 is a flow chart of the first embodiment;

FIG. 5 is a schematic diagram of CCD of the first embodiment;

FIG. 6 is a schematic diagram of 2-segment CCD of the first embodiment;

FIG. 7 is a diagram showing first correction approximate straight-linegroup information of the first embodiment;

FIG. 8 is a diagram showing a plurality of first correction approximatestraight-line group information of the first embodiment;

FIG. 9 is a diagram showing final correction approximate straight-linegroup information of the first embodiment;

FIG. 10 is a diagram showing adjacent pixels of the first embodiment;

FIG. 11 is a flow chart of a second embodiment;

FIG. 12 is a concrete functional block diagram of the first example ofthe second embodiment;

FIG. 13 is a diagram exemplifying arrangement 1 of the complementarycolor filter of the first example of the second embodiment;

FIG. 14 is a diagram exemplifying arrangement 2 of the complementarycolor filter of the first example of the second embodiment;

FIG. 15 is a schematic diagram of the first embodiment;

FIG. 16 is a functional block diagram of the first embodiment;

FIG. 17 is a schematic diagram of the second embodiment; and

FIG. 18 is a functional block diagram of the second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described hereinbelow withreference to the drawings. The present invention is not to be limited tothe embodiments and can be embodied in various forms without departingfrom the scope thereof.

First Embodiment

Hereinbelow, a first embodiment of the present invention will bedescribed.

Hereinbelow, a concept of the first embodiment will be described. Whencarrying out correction of output values for pixel of segmented blocksof CCD (after-mentioned), it is basically necessary to set appropriatecorrection approximate straight-line group information to respectiveapparatuses in a factory. The first embodiment relates to the generatingmethod and apparatus for the appropriate correction approximatestraight-line group information.

FIG. 15 is a schematic diagram of the first embodiment. In adjustmentbefore shipment, a generating apparatus for correction approximatestraight-line group information for multi-segment reading CCD 1501irradiates illuminant color for correction (e.g., red, green, or blue)to a multi-segment CCD 1502, and acquires output values for pixel(after-mentioned) from the CCD. Subsequently, a plurality of firstcorrection approximate straight-line group information (e.g., red,green, or blue) are generated based on difference of the acquired outputvalues for pixel occurring between segmented blocks. Subsequently, theone final correction approximate straight-line group information isgenerated from the plurality of first correction approximatestraight-line group information (e.g., red, green, or blue). The reasonfor generating the one final correction approximate straight-line groupinformation from the plurality of first correction approximatestraight-line group information is that first correction approximatestraight-line group information of a closer color differs depending onthe ratio of output values for pixel (so-called color components orcarrier components). For example, as to the after-mentionedcomplementary color filter, in the case of generating final correctionapproximate straight-line group information as to a pixel type C1, thefinal correction approximate straight-line group information is to begenerated from first correction approximate straight-line groupinformation of red and of green. The reason for this is that it dependson the ratio of output values for pixel as to the pixel type C1 to C2 tocarry out appropriate correction, correction to make a red-tinged coloror correction to make a green-tinged color. Therefore, in the case ofcorrection to make a red-tinged color, the final correction approximatestraight-line group information, which is close to the first correctionapproximate straight-line group information of red, is generated, and inthe case of correction to make a green-tinged color, the finalcorrection approximate straight-line group information, which is closeto the first correction approximate straight-line group information ofgreen, is generated.

Hereinbelow, a concept of correction approximate straight-line groupinformation of the present invention will be exemplified.

FIGS. 1, 2, and 3 are diagrams showing concept of correction approximatestraight-line group information, and explain the case where a CCD issegmented into right and left blocks.

FIG. 1 is a diagram showing a pixel, which is a target for usingcorrection approximate straight-line group information, and is used forgenerating correction approximate straight-line group information. A2-segment CCD (0100) is configured by a left-block L-CCD (0101) and aright-block R-CCD (0102). The L-CCD comprises a pixel A (0103) and theR-CCD comprises a pixel B (0104). Here, it is assumed that the pixel A(0103) and the pixel B (0104) are the same type of pixel (e.g., thecomplementary color filter C: Mg+Ye), and an output value a for pixelcorresponds to the pixel A, and an output value b for pixel correspondsto the pixel B. Considering a property of CCD, there is a gaindifference between the output values a and b for pixel. In order tocompensate the gain, K is added to the output value a for pixel.Therefore, a corrected output value d for pixel of the pixel A isexpressed by a formula d=a+K, and by plotting K according to an amountof received light on the pixel A, correction approximate straight-linegroup information is acquired.

FIG. 2 is a schematic diagram showing correction approximatestraight-line group information of the first embodiment. In cases wherean output value a1 for pixel corresponding to the pixel A in the leftblock is corrected based on an input value, in FIG. 2, K1, whichcorresponds to K, is added to the output value a1 for pixel (a correctedoutput value d1 for pixel corresponding to the pixel A is expressed by aformula d1=a1+K1), so that the same output value for pixel as the outputvalue b1 for pixel corresponding to the pixel B in the right block isoutputted to a display.

FIG. 3 is a diagram exemplifying the relation between CCD pixels andcorrected values in the case of carrying out correction by means ofcorrection approximate straight-line group information. Pixel number inCCD, pixel type, output value for pixel, correction approximatestraight-line group information to be used, value for correction, andcorrected value are included in one set. For example, as to a pixel, ofwhich a pixel number in CCD is 10000, its output value for pixel is a1when its pixel type is C1, and one correction approximate straight-linegroup information acquired according to its pixel type is f1. Further, avalue for correction acquired by means of the one correction approximatestraight-line group information is +K1, and a corrected output value forpixel is a1+K1.

Hereinbelow, components of the first embodiment will be described.

FIG. 16 is a functional block diagram of the generating apparatus forcorrection approximate straight-line group information for multi-segmentreading CCD of the first embodiment. A generating apparatus forcorrection approximate straight-line group information for multi-segmentreading CCD 1600 comprises a selecting unit for illuminant color forcorrection 1601, an irradiating unit for illuminant color for correction1602, a calculating unit for output difference 1603, a generating unitfor first correction approximate straight-line group information 1604,and a generating unit for final correction approximate straight-linegroup information 1605.

Prior to describing the components, CCD (Charge Coupled Device) will bedescribed.

A ‘CCD’ is an imaging sensor, which converts light into charge byphotoelectric effect.

FIG. 5 is a schematic diagram of general CCD. A CCD 500 comprises areceiving unit 0501, a vertical transferring unit 0502, and a horizontaltransferring unit 0503. In CCD, photodiodes (light receiving element),which is for sensing brightness (signal intensity of light), areregularly arranged in a matrix in a plane. The CCD is classified intoframe transfer-type CCD, interline transfer-type CCD, full frametransfer-type CCD, or frame interline transfer-type CCD etc. The lightreceiving unit comprising a plurality of light receiving elementsreceives light from an object, and converts light into charge byphotoelectric effect. The charge, which has been converted, istransferred to the vertical transferring unit. Charges in an initial oneline 0504 (a portion surrounded by perforated lines in FIG. 5, and alsoknown as line) of the charges transferred to the vertical transferringunit are transferred to the horizontal transferring unit. The horizontaltransferring unit outputs the charges in the initial one line to asignal amplification circuit etc. as charges corresponding to onescanning line. When the charges are transferred from the horizontaltransferring unit to the signal amplification circuit etc., charges inthe subsequent one line are transferred from the vertical transferringunit to the horizontal transferring unit. The above processes arerepeated for all lines of the vertical transferring unit. Thus, the CCDcompletes transfer of all charges within a predetermined period of time,and outputs charges in one frame (or one field). For example, in caseswhere CCD is used for an imaging sensor of recording apparatus forrecording a moving image such as a video camera, transfer of charges inone frame is completed within 1/30 sec. The charges outputted from theCCD are amplified up to a predetermined output value for pixel by thesignal amplification circuit, and necessary image processing is carriedout by circuits.

Here, the light receiving element can store only information regardingintensity of light, so that information regarding color cannot beacquired (i.e., it can store only amount of charges, which is describedas an output value for pixel in this specification (after-mentioned)).Therefore, in order to express a color, the CCD is configured tophotodegrade light by means of a primary color filter or a supplementarycolor filter, and to generate color information by means of acombination of color information of a plurality of pixels (e.g., in aportion 0505 surrounded by perforated lines in FIG. 5, the supplementarycolor filter expresses one color by a plurality of light receivingelements). Here, the term ‘primary color filter’ means filters of R(Red), G (Green), and B (Blue), which are the three primary colors oflight. For example, as described above, the light receiving element ofthe CCD is unable to identify color, so that RGB filter is equipped witha digital camera in order to acquire color information. Further, as tothe arrangement pattern of color filters with respect to each pixel ofthe CCD, even in the case of a normal RGB primary color filter, thecolor filters are arranged not in order of RGB, and there are usuallytwice as many Green filters as other color filters because the human eyeis most sensitive to green. Vividness is a characteristic of the primarycolor filter. However, in the case of a low-resolution CCD, whenenlarging a photographed image, the above arrangement pattern can appearas noise. Further, the primary color filter has low light transparency,thereby having a tendency of low sensitivity. Subsequently, the term‘complementary color filter’ includes filter of G (Green) in addition tofilters of Cy (Cyan, Green and blue), Mg (Magenta, Blue and Red), and Ye(Yellow, Green and Red), which are complementary colors of the threeprimary colors of light (refer to a portion 0505 surrounded byperforated lines in FIG. 5). In the case of using the complementarycolor filter, calculation of the output values for pixel of Cyan,Magenta, and Yellow is carried out, thereby generating the output valuesfor pixel of Red, Green and Blue. In the case of using complementarycolor filter, RGB is reproduced after the calculation, thereby causingloss in color reproduction, so that vividness as in the primary colorfilter cannot be reproduced, and its color tone is poor. Further, in thecalculation process, color tone becomes narrow and unnatural. Meanwhile,the complementary color filter has high light transparency, and thecalculation is carried out by adding green, which is a color includingthe most brightness information for the human eye, so that thecomplementary color filter generally has high sensitivity. In addition,as to the complementary color filter, sharpness tends to be calculatedin generating an image, so that the complementary color filter generallyhas high resolution. For example, an image photographed by a digitalcamera equipped with the complementary color filter CCD generally hashigh sharpness and natural color tone.

Hereinbelow, the components of the present invention will be described.

The ‘selecting unit for illuminant color for correction’ selects aplurality of illuminant colors in accordance with said pixel type ofCCD. Here, the term ‘illuminant color for correction’ means anilluminant color used for generating first correction approximatestraight-line group information (after-mentioned). Examples of theilluminant color for correction include white, red, green, blue, andyellow. Further, the term ‘pixel type’ means a type of a color filtercorresponding to color information of a pixel of CCD. Examples of thepixel type include red filter, green filter, and blue filter in the caseof using the primary color filter, and cyan filter, magenta filter,yellow filter, and green filter in the case of using the complementarycolor filter. A plurality of illuminant colors for correction (e.g.,white, red, green, and blue) are selected with respect to each pixeltype (e.g., cyan filter, magenta filter, yellow filter or green filter).The selected plurality of illuminant colors for correction are used inthe irradiating unit for illuminant color for correction.

The ‘irradiating unit for illuminant color for correction’ irradiates anilluminant color for correction selected in said selecting unit forilluminant color for correction to said CCD. Further, the lightintensity of the illuminant color for correction to be irradiated can beset arbitrarily. The irradiated illuminant color for correction is usedin the calculating unit for output difference.

The ‘calculating unit for output difference’ calculates an outputdifference between the segment reading blocks with respect to eachilluminant color for correction based on the illuminant color forcorrection irradiated in said irradiating unit for illuminant color forcorrection. The output difference of output value for pixel is used inthe generating unit for first correction approximate straight-line groupinformation.

Here, the term ‘segment reading’ means that the light receiving unit ofCCD is segmented into a plurality of blocks, and corresponding to this,the vertical transferring unit and horizontal transferring unit are alsosegmented into a plurality of blocks, and output values for pixel(after-mentioned) are outputted. Note that in cases where the divisionis only in the vertical direction, it is unnecessary to segment thevertical transferring unit, and in cases where the division is only inthe horizontal direction, it is unnecessary to segment the horizontaltransferring unit. Examples of the division include 2-segment,3-segment, and 4-segment. The purpose of the segmentation is to transferthe output values for pixel in one frame (or in one field) within apredetermined period of time even when number of pixels of CCD is large.For example, in the case of 2-segment CCD, the light receiving unit issegmented into 2 blocks, right and left blocks, and corresponding tothis, the vertical transferring unit and the horizontal transferringunit are also segmented into 2 blocks, right and left blocks,respectively, so that it becomes possible to segment the output valuesfor pixel in one line into output values for pixel of the left-block andof the right-block, and to transfer them. This CCD having the 2-blockhorizontal transferring unit is able to complete transfer within a halfperiod of time in comparison with a CCD, which has the same number ofpixels and 1-block horizontal transferring unit (a CCD, of which lightreceiving unit and horizontal transferring unit are not segmented into 2portions).

Further, the term ‘output difference between the segment reading blocks’means level differences of output values for pixel occurring between aplurality of blocks. These level differences mainly occur due todifferent signal paths for outputting the output value for pixel. Forthis reason, in cases where correction is not carried out, whenreproducing and displaying the output values for pixel, brightness isdifferent between a plurality of blocks in one image, therebydeteriorating image quality. Therefore, in the present invention, bycorrecting the output values for pixel of a plurality of blocks,differences of the output values for pixel occurring between a pluralityof blocks are corrected.

Subsequently, the output value for pixel will be described. The term‘output value for pixel’ means a signal value to be outputted to a pixelconfiguring a displaying apparatus for displaying an image. The outputvalue for pixel may be a value of unit of pixel (light receivingelement) configuring the multi-segment reading CCD, or may be a valueacquired by calculation (e.g., addition or subtraction etc.) of theoutput values for pixel of a plurality of pixels (light receivingelements). For example, correction process may be carried out afterconverting the output values for pixel of four types of pixels, Cy, Mg,Ye and G, which has been used for the complementary color filter, to theoutput values for pixel of C1: Mg+Ye, C2: G+Cy, C3: Mg+Cy, and C4: G+Ye.Alternatively, the correction process may be carried out afterconverting the output values for pixel of the four types of pixels, Cy,Mg, Ye and G, which have been used for the complementary color filter,into the output values for pixel of three types of pixels, R, G and B,which are the primary colors.

The ‘generating unit for first correction approximate straight-linegroup information’ generates first correction approximate straight-linegroup information Here, the term ‘first correction approximatestraight-line group information’ means information regarding straightline group used for generating one final correction approximatestraight-line group information. The first correction approximatestraight-line group information is generated based on the outputdifference calculated by the calculating unit for output difference.Further, a plurality of first correction approximate straight-line groupinformation are generated with respect to each illuminant color forcorrection. For example, in the case of using the primary color filter,all pixels are configured by repetition of three colors, R (Red), G(Green) and B (Blue), so that a plurality of first correctionapproximate straight-line group information are generated as to thethree colors, R, G and B, or as to a combination of R, G, and B.Further, in the case of using the complementary color filter, all pixelsare configured by repetition of four colors, Cy (Cyan, Green and blue),Mg (Magenta, Blue and Red), Ye (Yellow, Green and Red) and G (Green), sothat a plurality of first correction approximate straight-line groupinformation are generated as to the four colors, Cy, Mg, Ye and G, or asto a combination of Cy, Mg, Ye and G. Note that the output differencebetween the average values of the output values for pixel in the centralpixel area of the segmented block, which is used as a standard, and theaverage value of the output values for pixel in the central pixel areaof another block is calculated with respect to each pixel type, andirradiation intensity of the illuminant color for correction is changed,so that the first correction approximate straight-line group informationis generated. The first correction approximate straight-line groupinformation is used in the generating unit for final correctionapproximate straight-line group information.

Hereinbelow, a generating method for first correction approximatestraight-line group information will be described. As a simple example,the first correction approximate straight-line group information incases where the multi-segment reading CCD is segmented into right andleft blocks, will be described. Note that in this specification, unlessotherwise noted, a capital alphanumeric character is used for expressinga specific pixel, and a lower-case alphanumeric character correspondingto the capital alphanumeric character is used for expressing an outputvalue for pixel corresponding to the specific pixel. Further, in thisspecification, pixel type is expressed in brackets. For example, a‘pixel A’ means that a pixel, of which position is to be specified, isA, and ‘a’ means that an output value for pixel of the pixel A is a, oran output value for pixel of the pixel type A is a. Further, a ‘pixel(A1)’ means that a pixel type is A1. Further, a ‘pixel A (A1)’ meansthat a pixel type of the pixel A is A1.

FIG. 6 is a schematic diagram of 2-segment CCD of the first embodiment.a 2-segment CCD (0600) is segmented into a L-CCD (0601) and a R-CCD(0602). For example, it is assumed that all pixels of 2-segment CCD areconfigured by four types of pixels (A1), (A2), (A3), and (A4).Therefore, the four types of pixels (A1), (A2), (A3), and (A4) expressone color. Here, the central pixel area of the 2-segment CCD issegmented into a left-central pixel area 0603, and a right-central pixelarea 0604. The left-central pixel area 0603 and the right-central pixelarea 0604 comprise four types of pixels (A1), (A2), (A3), and (A4),respectively. In generating first correction approximate straight-linegroup information, at the outset, output values for pixel in theleft-central pixel area and in the right-central pixel area are measuredwith respect to each pixel type. For example, average values of theoutput values for pixel of the pixel (A1) in the left-central pixel areaand of the output values for pixel of the pixel (A1) in theright-central pixel area are calculated, and the difference between themis calculated. Subsequently, irradiation intensity of illuminant colorfor correction to be irradiated on the pixel (A1) is changed, and theaverage values of the output values for pixel are plotted on ahorizontal axis, and gain differences of the output values for pixelbetween the right and left blocks are plotted on a vertical axis, sothat the first correction approximate straight-line group information ofthe pixel (A1) is generated. The above processes are repeated as to aplurality of colors to be used for correction (illuminant colors forcorrection) of an entire object, so that a plurality of first correctionapproximate straight-line group information are generated. Further, theabove processes are carried out with respect to each type of pixels(A2), (A3), and (A4), so that a plurality of first correctionapproximate straight-line group information as to each type of pixel(A2), (A3), and (A4) are generated.

FIG. 7 is a diagram showing a generating method for first correctionapproximate straight-line group information (in the case of 2-segmentCCD). The horizontal axis indicates output value for pixel, and thevertical axis indicates gain difference of the output values for pixelbetween the right and left pixels. At the outset, output value for pixelof a specific color to be used for correction (illuminant color forcorrection) from an object is increased from L1 to L4. As the outputvalue for pixel changes, the right-and-left gain difference changes fromG1 to G4. An intersection of L1 with G1 is P1 (the same is applied toP2, P3, and P4). The P1, P2, P3, and P4 are connected by a straightline, thereby generating first correction approximate straight-linegroup information. The first correction approximate straight-line groupinformation is stored in a memory. As to the other colors to be used forcorrection (illuminant colors for correction), the first correctionapproximate straight-line group information is generated.

FIG. 8 is a diagram showing first correction approximate straight-linegroup information as to the pixel (A1) including first correctionapproximate straight-line group information as to a plurality of colorsto be used for correction (illuminant colors for correction: white, red,green, and blue). Similarly, as to the other types of pixels, (A2),(A3), and (A4), a plurality of first correction approximatestraight-line group information are generated.

Note that in the present invention, sizes of the left-central pixel areaand the right-central pixel area can be set arbitrarily. Further, in thepresent invention, a pixel area used for generating the first correctionapproximate straight-line group information is not limited to a centralportion. Therefore, the pixel area may be separately arranged in rightand left portion. Further, although the pixel area used for generatingthe first correction approximate straight-line group information may bethe smallest number of pixel areas necessary for generating the firstcorrection approximate straight-line group information (e.g., in thecase of using four types of pixels, (A1), (A2), (A3), and (A4), the fourtypes of pixels in respective right and left portions are used), it ispreferable to use a plurality of pixels and average values.

The ‘generating unit for final correction approximate straight-linegroup information’ generates one final correction approximatestraight-line group information with respect to each said pixel typebased on the plurality of first correction approximate straight-linegroup information generated in said generating unit for first correctionapproximate straight-line group information. Here, the term ‘finalcorrection approximate straight-line group information’ means thatcorrection approximate straight-line group information finally used forphotographing an object. Hereinbelow, a generating method for one finalcorrection approximate straight-line group information with respect toeach pixel type based on the plurality of first correction approximatestraight-line group information will be described. For generating onefinal correction approximate straight-line group information, forexample, ratio of color component (carrier component) is used. Forexample, in the case of using four types of pixels (A1), (A2), (A3), and(A4), the above-mentioned ratios, a1/a2 and a3/a4 are used. This hasbeen determined from an experimental result that difference betweenblocks due to property of CCD or to variation from analog circuit isapproximately proportional to ratio of carrier component. Hereinbelow,the generating method for final correction approximate straight-linegroup information will be described with reference to drawings.

FIG. 9 is a diagram showing final correction approximate straight-linegroup information. As a simple example, the case of generating finalcorrection approximate straight-line group information from firstcorrection approximate straight-line group information of red and ofgreen as to the pixel type A1 will be described. In FIG. 9, as to theoutput value a1 for pixel, right-and-left gain differences of the outputvalues for pixel of the first correction approximate straight-line groupinformation of red and of green are G1 and G2, respectively. In thiscase, for example, G3, the right-and-left gain difference of the outputvalues for pixel of the final correction approximate straight-line groupinformation, is acquired as (G1+G2)/2. By plotting this value varyingthe output value a1 for pixel, the one final correction approximatestraight-line group information of the pixel (A1) is generated.Similarly, as to the other types of pixels, (A2), (A3) and (A4), thefinal correction approximate straight-line group information isgenerated, respectively. Further, the above calculation of G3 may becarried out by means of a plurality of first correction approximatestraight-line group information based on the output values for pixel.Here, the term ‘based on the output values for pixel’ means that theoutput values for pixel may not be limited to value of the pixel usedfor generating the first correction approximate straight-line groupinformation, and may include values acquired by a predeterminedcalculation on the output values for pixel of the above pixel itself andof adjacent pixels. Further, in cases where a certain pixel A istargeted, the ‘adjacent pixels’ includes pixels next to A, severalpixels away from A in a horizontal direction, several pixels away from Ain a vertical direction, or several pixels away from A in a diagonaldirection. Further, examples of the ‘predetermined calculation’ includeratio of the output values for pixel of the pixel A itself to theadjacent pixel, and ratio of sum or difference of the output values forpixel of the pixel A itself to the adjacent pixel. For example, assumingthat the pixel to be targeted is A (the output value for pixel is a),and the adjacent pixel is B (the output value for pixel is b), examplesof the predetermined calculation include a/b, b/a, (a+b)/(a−b), and(a−b)/(a+b).

FIG. 10 is a diagram showing adjacent pixels of the first embodiment. ACCD (1000) is configured by four types of pixels, (A1), (A2), (A3), and(A4). The four types of pixels, (A1), (A2), (A3), and (A4) form a unit1001 for expressing a color, and these four types of pixels arerepeatedly arranged, thereby configuring all pixels. Here, it is assumedthat the ratio of the output values a1 to a2, a1/a2, is used. Forexample, if the pixel to be targeted is a target pixel 1002, theadjacent pixels are circled pixels (A2) in FIG. 10. Adjacent pixels 1003(A2) are next to the target pixel 1002 (A1). The other adjacent pixels,for example, an adjacent pixel 1004 (A2) is not next to the target pixel1002 (A1). In cases where the ratio of the output values a3 to a4,a3/a4, is used as a predetermined calculation, the above concept ofadjacent pixel is similar.

The correction is practically carried out by calculating correctionvalue from output values for pixel as to all pixels by means of onefinal correction approximate straight-line group information, which iscommon in respective pixel types and has been generated with respect toeach pixel type.

Hereinbelow, a processing flow of the first embodiment will bedescribed. Note that the after-mentioned processing flow can beimplemented as a method, as a program operated by a computer, or as areadable recording medium storing the program. (the same is applied tothe other processing flows in this specification).

FIG. 4 is a flow chart of the first embodiment.

In the generating method for correction approximate straight-line groupinformation for multi-segment reading CCD, at the outset, a selectingstep for illuminant color for correction (step S0401) selects aplurality of illuminant colors in accordance with said pixel type ofCCD. Subsequently, an irradiating step for illuminant color forcorrection (step S0402) irradiates a illuminant color for correctionselected in said selecting step for illuminant color for correction tosaid CCD. Subsequently, a generating step for first correctionapproximate straight-line group information (step S0403), which is forcorrecting output difference between segment reading blocks with respectto each pixel type, generates first correction approximate straight-linegroup information based on the illuminant color for correctionirradiated in said irradiating step for illuminant color for correction.Subsequently, a generating step for final correction approximatestraight-line group information (step S0404) generates one finalcorrection approximate straight-line group information with respect toeach said pixel type based on the plurality of first correctionapproximate straight-line group information generated in said generatingstep for first correction approximate straight-line group information.

According to the method and an apparatus for generating correctionapproximate straight-line group information for multi-segment readingCCD, it becomes possible to generate a plurality of first correctionapproximate straight-line group information with respect to eachapparatus. The best one final correction approximate straight-line groupinformation is generated from the generated plurality of firstcorrection approximate straight-line group information. Therefore, as toall pixels, it becomes possible to carry out correction with respect toeach pixel type by means of the one final correction approximatestraight-line group information upon photographing.

Second Embodiment

Hereinbelow, the second embodiment will be described.

Hereinbelow, a concept of the second embodiment will be described. Whencarrying out correction of output value for pixel of segmented blocks ofCCD (after-mentioned), it is basically necessary to set appropriatecorrection approximate straight-line group information to respectiveapparatuses in a factory. The second embodiment relates to thegenerating method and apparatus for the appropriate correctionapproximate straight-line group information.

FIG. 17 is a schematic diagram of the second embodiment. In adjustmentbefore shipment, a manufacturing apparatus for correction processingequipment for multi-segment reading CCD 1701 irradiates illuminant colorfor correction (e.g., red, green, or blue) to a multi-segment CCD 1702,and acquires output values for pixel from CCD. Subsequently, a pluralityof first correction approximate straight-line group information (e.g.,red, green, or blue) are generated based on difference of the acquiredoutput value for pixel occurring between segmented blocks. Subsequently,the best one final correction approximate straight-line groupinformation is generated from the plurality of first correctionapproximate straight-line group information (e.g., red, green, or blue),and is stored in a memory unit of the correction processing equipmentfor multi-segment reading CCD. Note that the reason for generating thebest one final correction approximate straight-line group informationfrom the plurality of first correction approximate straight-line groupinformation is the same as that of the first embodiment, so that thedescription will be omitted.

Hereinbelow, components of the second embodiment will be described.

FIG. 18 is a functional block diagram of the second embodiment. Amanufacturing apparatus for correction processing equipment formulti-segment reading CCD 1800 comprises a preparing unit for CCD 1801,a selecting unit for illuminant color for correction 1802, anirradiating unit for illuminant color for correction 1803, a generatingunit for first correction approximate straight-line group information1804, a generating unit for final correction approximate straight-linegroup information 1805, and a storing unit 1806.

Hereinbelow, the components of the second embodiment will be described.

The ‘selecting unit for illuminant color for correction’, the‘irradiating unit for illuminant color for correction’, the ‘generatingunit for first correction approximate straight-line group information’,and the ‘generating unit for final correction approximate straight-linegroup information’ are the same as those of the first embodiment, sothat the description will be omitted.

The ‘preparing unit for CCD’ prepares a CCD to be corrected by thecorrection processing equipment. The prepared CCD is used in outputtingto the irradiating unit for illuminant color for correction. Here, theterm ‘CCD’ is the same as that of the first embodiment, so that thedescription will be omitted.

The ‘storing unit’ stores the final correction approximate straight-linegroup information correlated with said CCD, which has been acquired bysaid generating unit for final correction approximate straight-linegroup information, into a memory unit of the correction processingequipment. Here, examples of the ‘memory unit’ include an EEPROM and anon-volatile memory. Here, the terms ‘correlated with CCD’ means thatthe final correction approximate straight-line group information usedfor correction as to respective pixels in CCD is correlated with therespective pixels.

Example

Hereinbelow, the first example of the second embodiment will bedescribed. In the first example, the correction processing equipment for2-segment reading CCD manufactured by the method of the secondembodiment will be described.

FIG. 12 is a functional block diagram of the correction processingequipment 1200 for 2-segment reading CCD of the first example. Thecorrection processing equipment for 2-segment reading CCD of the firstexample comprises a 2-segment reading CCD 1201, a 2-block CDS(Correlated Double Sampling)/ADC (Analog Digital Conversion) circuit1205, a gain detecting circuit 1206, a non-volatile memory (e.g.,EEPROM) 1207, a control microcomputer 1208, a gain correcting circuit1209, a rearranging circuit for pixel 1210, and a CCD signal processingcircuit 1211.

In addition, the 2-segment reading CCD 1201 comprises a light receivingelement (photodiode) and a vertical transferring CCD 1202, andhorizontal transferring CCDs 1203 and 1204. The light for photographingfrom an object is photoelectric converted by the light receiving element1202, and is stored as charge. This charge is transferred to thevertical transferring CCD 1202 at a timing. The vertical transferringCCD 1202 is divided into two portions, right and left portions, and thecharges in the left-half of vertical transferring CCD are transferred tothe left-half of the horizontal transferring CCD 1203, and the chargesin the right-half of vertical transferring CCD are transferred to theright-half of the horizontal transferring CCD 1204 at a timing ofrespective lines. The horizontal transferring CCDs 1203 and 1204transfers the transferred charges, respectively, and the charges areoutputted as voltage signals though amplifiers of right and left sides.The outputted signal is transferred to the 2-block CDS/ADC circuit 1205,and digitalized. The outputted signal is A/D converted, and is read inthe respective blocks, so that level difference occurs It is known thatthis level difference occurs in the CCD and in the A/D conversioncircuit, and is dependent on the output level of the light receivingelement (Jpn. unexamined patent publication No. 2002-320412). Further,it has been confirmed by an experiment that the difference changes dueto the color component (carrier component, output value for pixel of atype of pixel). Moreover, it changes due to a property of a board. Theabove processes are common in generating the final correctionapproximate straight-line group information and in normal photographing.

Subsequently, the generation of the final correction approximatestraight-line group information will be described. In the generation ofthe final correction approximate straight-line group information, at theoutset, in order to generate a plurality of first correction approximatestraight-line group information, a uniform object (e.g., a screen),which has a large carrier component (e.g., red, green or blue) isphotographed. Here, three colors (e.g., red, green and blue) arecaptured, and from them, the first correction approximate straight-linegroup information as to pixels (C1: Mg+Ye), (C2: G+Cy), (C3: Mg+Cy), and(C4: G+Ye) are generated, respectively. In the first example, red, greenand blue are captured, and as to the pixels (C1) and (C2), the one finalcorrection approximate straight-line group information is generated fromthe first correction approximate straight-line group information of redand of blue with respect to each pixel type, and as to the pixels (C3)and (C4), the one final correction approximate straight-line groupinformation is generated from the first correction approximatestraight-line group information of blue and of green with respect toeach pixel type. The final correction approximate straight-line groupinformation is generated by means of ratio of the carrier component(after-mentioned). This final correction approximate straight-line groupinformation is stored in the non-volatile memory, and in normalphotographing, the control microcomputer 1208 sets the final correctionapproximate straight-line group information stored in the non-volatilememory to the gain correcting circuit.

Hereinbelow, the carrier component will be described. As an example, aCCD using a complementary color filter will be described.

FIGS. 13 and 14 are diagrams exemplifying arrangements of thecomplementary color filter. Normally, an arrangement of thecomplementary color filter is as shown in FIG. 13, and in shootingmoving image, output values for pixel in a vertical direction are added,so that output in an arrangement as shown in FIG. 14 is carried out.Therefore, as to a certain line, the output value c1 for pixel of thepixel (C1: Mg+Ye) and the output value c2 for pixel of the pixel (C2:G+Cy) are alternately outputted. As to a subsequent line, the outputvalue c3 for pixel of the pixel (C3: Mg+Cy) and the output value c4 forpixel of the pixel (C4: G+Ye) are alternately outputted. Inphotographing a still image, as to a certain field, the output value d1for pixel of (Mg) and the output value d2 for pixel of (G) arealternately outputted. As to a subsequent field, the output value d4 forpixel of (Ye) and the output value d3 for pixel of (Cy) are alternatelyoutputted. In cases where an object, which has fewer carrier components(e.g., white), is photographed, their ratios in a horizontal directionare close to 1. For example, in shooting moving image, c1/c2=1, andc3/c4=1. (This is the same as in the case of a primary color CCD. In thecase of the primary color, as to a certain line, the output value e1 forpixel of (R) and the output value e2 for pixel of (G) are alternatelyoutputted. As to a subsequent line, the output value e4 for pixel of (G)and the output value e3 for pixel of (B) are alternately outputted. Inthe case of the object, which has fewer carrier components, e1/e2=1, ande3/e4=1.) Here, from the average value of data of right and leftportions of a CCD central area 1213 in FIG. 12 (e.g., average value asto each of the output value c1 for pixel of the pixel C1, the outputvalue c2 for pixel of the pixel C2, the output value c3 for pixel of thepixel C3, and the output value c4 for pixel of the pixel C4), and as tothe right-and-left gain difference (e.g., right-and-left gaindifferences as to the output values c1, c2, c3 and c4 for pixel of thepixels C1, C2, C3 and C4), average values of the gain differences areacquired, and from them, the first correction approximate straight-linegroup information are generated (e.g., as to each of the pixel (C1),(C2), (C3) and (C4), the first correction approximate straight-linegroup information is generated). In addition, ratio of carrier componentin a horizontal direction at this point is also recorded. Therefore, asto the case of photographing an object, which has large carriercomponent, measurement is carried out changing amount of light forphotographing, thereby calculating the ratio of the output values forpixel c1/c2 and c3/c4. Note that the values of c1, c2, c3 and c4 usedfor calculating the ratios of lines c1/c2 and c3/c4 are the averagevalues of c1, c2, c3 and c4 when one of the right or left portion of theCCD central area is set as a standard.

Subsequently, calculation of the final correction approximatestraight-line group information will be described. In the first example,by means of detection result of an object by a plurality of colors, thefinal correction approximate straight-line group information isacquired. Hereinbelow, the case of acquiring the output value for pixelfrom the object having a plurality of colors will be described. In caseswhere the output values for pixel detected in the gain detecting circuit(1206) are the same, for example, in the case of the pixel (C1), red hasthe largest right-and-left gain difference of YCrCb outputted from theCCD signal processor (1211) in comparison with other colors of theobject. Therefore, as to the pixel (C1), red has the largest effect onthe right-and-left gain difference in comparison with the other colors.In acquiring the final correction approximate straight-line groupinformation, the largest ratio is given to red, which is the mosteffective color. As shown in FIG. 9, since red and green have largecarrier components, the first correction approximate straight-line groupinformation in cases where the object is red and the first correctionapproximate straight-line group information in cases where the object isgreen are acquired. Then, the final correction approximate straight-linegroup information is acquired so as to be close to red, which is themost effective on the right-and-left gain difference. Thus, the finalcorrection approximate straight-line group information as to the pixels(C1) to (C4) is acquired with respect to each pixel type, so that theright-and-left gain difference becomes small at the final output levelYCrCb. To be exact, there are errors, which are away from the finalcorrection approximate straight-line group information, as to somecolors. However, the colors are less effective, so that it becomespossible to reduce the right-and-left gain differences, comprehensively.Therefore, comparing with the conventional detection method by means ofsingle color such as white, the above-mentioned method enables reductionof errors in the right-and-left gain differences.

In addition, in the gain detecting circuit (1206) of FIG. 12, ifdifference of noise amplitude between the right and left block isdetected, noise is added and adjustment is carried out so as to levelthe amplitudes of input signals of the right and left blocks in the gaincorrecting circuit (1209), thereby enabling correction of theright-and-left gain difference

Hereinbelow, a processing flow of the second embodiment will bedescribed.

FIG. 11 is a flow chart of the second embodiment.

In the manufacturing method for correction processing equipment formulti-segment reading CCD, at the outset, a preparing step for CCD (stepS1101) prepares a CCD to be corrected by the correction processingequipment. Subsequently, a selecting step for illuminant color forcorrection selects a plurality of illuminant colors in accordance withsaid pixel type of CCD (step S1102). Subsequently, an irradiating stepfor illuminant color for correction irradiates a illuminant color forcorrection selected in said selecting step for illuminant color forcorrection to said CCD (step S1103). Subsequently, a generating step forfirst correction approximate straight-line group information generatesfirst correction approximate straight-line group information based onthe illuminant color for correction irradiated in said irradiating stepfor illuminant color for correction (step S1104). Subsequently, agenerating step for final correction approximate straight-line groupinformation generates one final correction approximate straight-linegroup information with respect to each pixel type based on the pluralityof first correction approximate straight-line group informationgenerated in said generating step for first correction approximatestraight-line group information (step S1105). Subsequently, a storingstep stores the final correction approximate straight-line groupinformation correlated with said CCD, which has been acquired in saidgenerating step for final correction approximate straight-line groupinformation, in a memory unit of the correction processing equipment(step S1106).

According to the method and an apparatus for generating correctionapproximate straight-line group information for multi-segment readingCCD, it becomes possible to generate a plurality of first correctionapproximate straight-line group information with respect to eachapparatus. The best one final correction approximate straight-line groupinformation is generated from the generated plurality of firstcorrection approximate straight-line group information. Therefore, as toall pixels, it becomes possible to carry out correction with respect toeach pixel type by means of the one final correction approximatestraight-line group information upon photographing.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a method and an apparatus forgenerating correction approximate straight-line group information formulti-segment reading CCD, and a method and an apparatus formanufacturing correction processing equipment for multi-segment readingCCD.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A manufacturing method for correction processing equipment formulti-segment reading CCD, which is for correcting an output value forpixel acquired based on an output in accordance with a pixel type of themulti-segment reading CCD, comprising: a preparing step for themulti-segment reading CCD, which prepares the multi-segment reading CCDto be corrected by the correction processing equipment; a selecting stepfor illuminant color for correction, which selects a plurality ofilluminant colors in accordance with said pixel type of themulti-segment reading CCD; an irradiating step for illuminant color forcorrection, which irradiates a illuminant color for correction selectedin said selecting step for illuminant color for correction to saidmulti-segment reading CCD; a generating step for first correctionapproximate straight-line group information, which generates firstcorrection approximate straight-line group information based on theilluminant color for correction irradiated in said irradiating step forilluminant color for correction; a generating step for final correctionapproximate straight-line group information, which generates one finalcorrection approximate straight-line group information with respect toeach said pixel type based on the plurality of first correctionapproximate straight-line group information generated in said generatingstep for first correction approximate straight-line group information;and a storing step, which stores the final correction approximatestraight-line group information correlated with said multi-segmentreading CCD, which has been acquired in said generating step for finalcorrection approximate straight-line group information, in a memory unitof the correction processing equipment.
 2. A manufacturing apparatus forcorrection processing equipment for multi-segment reading CCD, which isfor correcting an output value for pixel acquired based on an output inaccordance with a pixel type of the multi-segment reading, comprising: apreparing unit for the multi-segment reading CCD, which prepares themulti-segment reading CCD to be corrected by the correction processingequipment; a selecting unit for illuminant color for correction, whichselects a plurality of illuminant colors in accordance with said pixeltype of the multi-segment reading CCD; an irradiating unit forilluminant color for correction, which irradiates a illuminant color forcorrection selected by said selecting unit for illuminant color forcorrection to said multi-segment reading CCD; a generating unit forfirst correction approximate straight-line group information, whichgenerates first correction approximate straight-line group informationbased on the illuminant color for correction irradiated by saidirradiating unit for illuminant color for correction; a generating unitfor final correction approximate straight-line group information, whichgenerates one final correction approximate straight-line groupinformation with respect to each said pixel type based on the pluralityof first correction approximate straight-line group informationgenerated by said generating unit for first correction approximatestraight-line group information; and a storing unit, which stores thefinal correction approximate straight-line group information correlatedwith said multi-segment reading CCD, which has been acquired by saidgenerating unit for final correction approximate straight-line groupinformation, into the correction processing equipment.